From: Colin Leroy <colin@colino.net>
To: Andi Kleen <ak@suse.de>
Cc: Matt Mackall <mpm@selenic.com>,
"David S. Miller" <davem@davemloft.net>,
ak@suse.de, akpm@osdl.org, netdev@oss.sgi.com
Subject: Re: [PATCH] Prevent netpoll hanging when link is down
Date: Fri, 8 Oct 2004 08:46:40 +0200 [thread overview]
Message-ID: <20041008084640.58976145@pirandello> (raw)
In-Reply-To: <20041007235022.GB19864@wotan.suse.de>
On 08 Oct 2004 at 01h10, Andi Kleen wrote:
Hi,
> > Deadlocks from recursion, presumably? We could probably throw in a
> > max retry count, as ugly as that is..
>
> There should not be any recursion, no.
If printk() is synchronous, there could be, if there's a printk() in the
codepath taken by dev->hard_start_xmit()... But I don't if it is...
> The problem is that the poll is effectively a spinlock. But when
> another CPU takes an long interrupt while holding the lock it
> could take quite a long time to grab the lock.
>
> For most network drivers this shouldn't occur though because
> the net driver private lock is usually always taken with interrupts
> off.
Second newbie question: how are the interrupts disabled, is it via
local_irq_save()/local_irq_restore()? or is it something else ?
--
Colin
next prev parent reply other threads:[~2004-10-08 6:46 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20041006232544.53615761@jack.colino.net>
2004-10-06 21:43 ` [PATCH] Prevent netpoll hanging when link is down Matt Mackall
2004-10-07 5:53 ` Colin Leroy
2004-10-07 6:49 ` David S. Miller
2004-10-07 8:33 ` Colin Leroy
2004-10-07 8:45 ` Colin Leroy
2004-10-07 14:05 ` Colin Leroy
2004-10-07 18:28 ` David S. Miller
2004-10-07 18:41 ` Matt Mackall
2004-10-07 20:00 ` Colin Leroy
2004-10-07 18:43 ` Andi Kleen
2004-10-07 20:44 ` Colin Leroy
2004-10-07 21:45 ` Andi Kleen
2004-10-07 21:50 ` Matt Mackall
2004-10-07 22:07 ` David S. Miller
2004-10-07 23:43 ` Matt Mackall
2004-10-07 23:50 ` Andi Kleen
2004-10-08 6:46 ` Colin Leroy [this message]
2004-10-08 21:53 ` Matt Mackall
2004-10-08 7:06 ` Colin Leroy
2004-10-08 22:00 ` Matt Mackall
2004-10-08 22:18 ` Andrew Morton
2004-10-11 3:59 ` David S. Miller
2004-10-11 15:40 ` Andi Kleen
2004-10-11 16:22 ` Matt Mackall
2004-10-11 16:32 ` Andi Kleen
2004-10-11 16:36 ` Matt Mackall
2004-10-11 16:43 ` Andi Kleen
2004-10-11 16:58 ` Matt Mackall
2004-10-11 17:41 ` Andi Kleen
2004-10-11 20:45 ` Colin Leroy
[not found] ` <5cac192f0410181443303379e2@mail.gmail.com>
[not found] ` <5cac192f041018145824acce5a@mail.gmail.com>
[not found] ` <20041020161119.6e30efe5@pirandello>
[not found] ` <5cac192f0410200848179ccc81@mail.gmail.com>
2004-10-21 16:36 ` Colin Leroy
2004-10-24 15:22 ` Eric Lemoine
2004-10-07 22:08 ` David S. Miller
2004-10-08 6:54 ` Colin Leroy
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